Disrupted redox homeostasis contributes to renal ischemia–reperfusion (IR) injury. Abundant natural products can activate nuclear factor erythroid-2-related factor 2 (Nrf2), thereby providing therapeutic benefits. Methyl eugenol (ME), an analog of the phenolic compound eugenol, has the ability to induce Nrf2 activity. In this study, we investigated the protective effects of ME against renal oxidative damage in vivo and in vitro. An IR-induced acute kidney injury (AKI) model was established in mice. ME (20 mg·kg⁻¹·d⁻¹, i.p.) was administered to mice on 5 consecutive days before IR surgery. We showed that ME administration significantly attenuated renal destruction, improved the survival rate, reduced excessive oxidative stress and inhibited mitochondrial lesions in AKI mice. We further demonstrated that ME administration significantly enhanced Nrf2 activity and increased the expression of downstream antioxidative molecules. Similar results were observed in vitro in hypoxia/reoxygenation (HR)-exposed proximal tubule epithelial cells following pretreatment with ME (40 μmol·L⁻¹). In both renal oxidative damage models, ME induced Nrf2 nuclear retention in tubular cells. Using specific inhibitors (CC and DIF-3) and molecular docking, we demonstrated that ME bound to the binding pocket of AMPK with high affinity and activated the AMPK/GSK3β axis, which in turn blocked the Nrf2 nuclear export signal. In addition, ME alleviated the development of renal fibrosis induced by nonfatal IR, which is frequently encountered in the clinic. In conclusion, we demonstrate that ME modulates the AMPK/GSK3β axis to regulate the cytoplasmic–nuclear translocation of Nrf2, resulting in Nrf2 nuclear retention and thereby enhancing antioxidant target gene transcription that protects the kidney from oxidative damage.

氧化还原稳态破坏会导致肾缺血再灌注（IR）损伤。丰富的天然产物可以激活核因子红细胞 2 相关因子 2 (Nrf2)，从而提供治疗效果。甲基丁香酚 (ME) 是酚类化合物丁香酚的类似物，具有诱导 Nrf2 活性的能力。在这项研究中，我们研究了 ME 对体内和体外肾脏氧化损伤的保护作用。在小鼠中建立了 IR 诱导的急性肾损伤 (AKI) 模型。在IR手术前连续5天向小鼠施用ME（20 mg·kg ^-1 ·d ^-1 ，腹膜内注射）。我们发现，ME 给药可显着减轻 AKI 小鼠的肾脏破坏，提高存活率，减少过度氧化应激并抑制线粒体损伤。我们进一步证明，ME 给药显着增强 Nrf2 活性并增加下游抗氧化分子的表达。在用ME（40 μmol·L ^-1 ）预处理后，在缺氧/复氧（HR）暴露的近曲小管上皮细胞中体外观察到类似的结果。在两种肾氧化损伤模型中，ME 诱导肾小管细胞中的 Nrf2 核滞留。使用特异性抑制剂（CC和DIF-3）和分子对接，我们证明ME以高亲和力与AMPK的结合袋结合并激活AMPK/GSK3β轴，进而阻断Nrf2核输出信号。此外，ME还减轻了临床上经常遇到的非致命性IR引起的肾纤维化的发展。 总之，我们证明 ME 调节 AMPK/GSK3β 轴来调节 Nrf2 的细胞质-核易位，导致 Nrf2 核保留，从而增强抗氧化靶基因转录，保护肾脏免受氧化损伤。